function [H] = channelGenerate(N_r, N_t, num)
% 信道生成，信道系数服从复高斯分布
    H = zeros(N_r, N_t, num);
    for index = 1 : num
        H(:,:,index)= sqrt(1/2)*(randn(N_r, N_t) + 1i * randn(N_r, N_t));
    end
end
